Project Summary/Abstract Polypharmacy among older adults is common and increases the likelihood of being prescribed and harmed by high-risk medications. To date, efforts to reduce the rate of high-risk polypharmacy have had limited uptake due to their expense per clinician and their modest effectiveness in helping clinicians stop potentially inappropriate medications. These prior efforts have relied on rational models of clinician behavior. However, like people in general, clinicians are susceptible to irrational biases and cognitive shortcuts that might perpetuate inappropriate high-risk polypharmacy. Therefore behavioral economic nudges, which do not assume rational decision making, might be well-positioned to reduce such high-risk polypharmacy. Moreover, such nudges can be embedded in electronic health records (EHRs), enhancing their scalability at a low cost per clinician?as long as they are acceptable to clinicians who worry about EHRs' effects on their workflows. The overall objectives of the project are to develop EHR-based behavioral economic nudges that reduce the prevalence and degree of high-risk polypharmacy among older adult patients, to test their effectiveness, and to describe their impact on clinicians' experiences and workflows. To do this, we will complete an R21 planning phase, followed by an R33 implementation phase. The specific aims of the 2-year R21 planning phase are (1) to specify, implement, and validate measures of high-risk polypharmacy within the Northwestern University EHR and (2) to develop and pilot two nudges within the Northwestern EHR (a commitment nudge and a justification nudge). The specific aims of the 3-year R33 implementation phase are (3) to refine the nudges within the Northwestern EHR and implement the nudges and high-risk polypharmacy measures within the Sutter Health EHR, (4) to evaluate the effects of each EHR-based nudge on measures of high-risk polypharmacy via randomized controlled trial, and (5) to assess qualitatively clinician experiences with the EHR-based nudges, including their acceptability and effects on workflow. To accomplish the R21 aims, our multidisciplinary team of researchers experienced in designing EHR- based measures of medication appropriateness and behavioral economic nudges will use the Northwestern EHR as a development and testing lab. After assessing their feasibility, we will (in the R33 phase) finalize both nudges and conduct an 18-month cluster randomized trial in which we randomize approximately 300 Northwestern and Sutter clinics across to receive 0, 1, or 2 nudges in a 2 x 2 factorial design. In the final project year we will conduct semi-structured interviews with approximately 40 clinicians to describe their experiences with the nudges in detail. The study will yield EHR-based nudges that can be implemented across the country, detailed descriptions of how these nudges affect clinicians' workflows, and scientific papers documenting the nudges' effectiveness in reducing high-risk polypharmacy among older adults.